110 MAMMALIA. 



FAMILY II. 



CETACEA OKD1NARIA. 



The Ordinary Cetncra are distinguished from the preceling by the singular 

 apparatus from which they have received the name of Bloirers. 

 As a large quantity of water passes into their huge mouths along 

 with their prey, some way was necessary by which they could get 

 rid of it ; accordingly, it passes through the nostrils by means of a 

 peculiar disposition of the velum palati, and is accumulated in a sac 

 situated at the external orifice of the cavity of the nose, whence, by 

 the compression of powerful muscles, it is violently expelled through 

 narrow opening on the top of the head. It is in this way they 

 'produce those jets d'eau observed by navigators at so great a distance- 

 Their nostrils, continually bathed in salt water, could not be lined with a mem- 

 brane sufficiently delicate to enable them to detect odours, and accordingly they 

 have none of those projecting laminae found in the nasal cavities of other 

 animals ; the olfactory nerve is deficient in several ; and if there be any which 

 enjoy the sense of smell, it must be in a very slight degree. Their larynx, of 

 a pyramidal form, penetrates into the posterior nares to receive air and conduct 

 it to the lungs, without compelling the animal to raise its head and throat 

 above the water for that purpose : there are no salient lamina: in the glottis, 

 and the voice is reduced to a simple lowing. They have no vestige of hairs ; 

 but their whole body is covered with a smooth skin, under which is that 

 thick layer of blubber abounding in oil, the principal object for which they 

 are pursued. 



The stomach is divided into five and sometimes into seven distinct sacs; 

 instead of one single spleen, they have several, small and globular ; those which 

 are possessed of teeth, have them all conical and alike; they do not chew 

 their food, but swallow it rapidly. 



Two small bones, suspended in the flesh, are the only vestiges of posterior 

 extremities. 



Several have a vertical fin on the back, composed of a tendinous substance? 

 but unsupported by bone. Their eyes, flattened in front, have a thick and 

 solid sclerotica ; the teguments of the tongue are soft and smooth. 



They may be again divided into two small tribes: those in which the head 

 bears the usual proportion to the body, and those in which it is immoderately 

 large. The first comprehends the Dolphins and the Narwhals. 



DELPHINUS, Linnaeus. 



The Dolphins have teeth in both jaws, all simple, and almost always conical. 

 They are the most carnivorous, and, in proportion to their size, the most cruel 

 of their order. 



